[ansel] Some more questions (faces)

[Michael J. Rubinsky]

Quoting Jan Seynaeve <jan.seynaeve at telenet.be>:

> While am playing away, some more questions now on the face thinggy.
>
> 1.
> I spent some blood, sweat and tears in installing opencv and  
> facedetect, but i think i have it now (at least, it shows up ok in  
> the test.php). But i can't see the magic :-(
> Can someone explain what "Find faces" and "Find similar" are  
> supposed to do? And/or maybe show me where i can look for errors?
> Find faces only gives me the faces i manually tagged and find  
> similar only gives a 30ish% similarity between different persons,  
> while i have a lot of other photo's with the same person on which i  
> expected to show up too ... is there any tuning to be done?

"Find Faces" just recognizes human faces in a photo.
"Find Similar" uses libpuzzle pecl extension to *attempt* to find  
photos that contain similar faces.  I say attempt because in my own  
tests it doesn't work spectacularly. It works by breaking an image (in  
this case, the small face-only image) down into small squares and  
creating a signature of each small set of pixels.  These signatures  
are stored in a database, linked to each face. If another image  
contains a high number of the same signautes, it's considered  
"similar". By using the small face-only picture, I think that it  
causes a high number of false positives. Not sure, just a guess. As  
far as tuning goes, if you like, you can tweak the size of each chuck,  
see if smaller chunks or larger chunks work better for you. This is  
the $conf[faces][search] value in Ansel's face config.  You can also  
change the definition file the opencv uses to detect faces by changing  
the value of $conf[faces][defs] .. I use the  
haarcascade_frontalface_alt.xml file when I enable the face detection  
feature.


> 2.
> I also tagged some faces manually, but if i give them the same name  
> they still show as "different" faces in the "People in this gallery"  
> window. Is this how it works? Shouldn't they be grouped or something?

Yea, unfortunately, right now this is the way it works... since the  
image is a link to the picture that contains the face. A possible  
enhancement would be to group all the faces with the same name, and  
link that to a search for that name, I guess.  For the "People in this  
gallery" widget, the existing behavior would remain.  Is this more of  
what you had in mind?  You can open an enhancement request on  
bugs.horde.org so that this doesn't get lost/forgotten about ;)


> 3.
> And then a bit off topic, on horde.org you have a nice pic of the  
> galleries shown like a "random bunch of photo's" from the gallery  
> itself ... how do you do that? Does it come with a style?

Yup. There are a number of available gallery styles.  From your  
description, it sounds like you are talking about the Polaroid-like  
style... with the gallery tile looking like a bunch of polaroids just  
thrown in a pile?  That requires the use of the imagemagick or imagick  
image driver, it's not supported with the GD driver.  (This is changed  
in Horde's config admin-setup->horde->Image manipulation)

Thanks for the feedback.

-- 
Thanks,
mike

--
The Horde Project (www.horde.org)
mrubinsk at horde.org